Many measurements require the use of a laser as a source of light. For example, lasers are used in systems ranging from imaging to the detection of gene sequences. In such systems various types of lasers are used, including gas lasers, chemical lasers, excimer lasers, solid-state lasers, semiconductor lasers (including diode lasers), dye lasers and hollow cathode sputtering metal ion lasers. Each type of laser has its own set of advantages and disadvantages when used for a specific application. For example, the characteristics of the different types of lasers including power output, wavelength, cost, size, tunability and uniformity of intensity over a cross-section of the beam are either advantages or disadvantages depending on the application in which the laser is used.
Diode lasers are low cost, have a relatively high power output and are small in size. A diode laser includes a radiating area or facet that has a very low aspect (height to width) ratio. That is, the height of the radiating facet is much smaller than its width. The beam produced by the laser diode facet is not uniform in intensity across the radiating facet. Because of the lack of uniformity in beam intensity, laser diodes cannot be used in applications where beam intensity uniformity is required. Therefore, in applications in which high power and uniformity are required other lasers such as gas lasers, which are more expensive and quite large, are generally used.
In many applications, decreasing the cost and size of the laser greatly decreases overall equipment and hence research costs. Thus, a method or system to decrease the detected non-uniformity in the intensity of a diode laser beam could increase the efficiency and decrease the size of the equipment used in selected applications.
The present invention addresses the problem of detected beam intensity non-uniformity in a laser beam of light.